JP2598032B2 - Processing method of refrigerant pipe in liquid tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an improvement in a method of processing a refrigerant pipe in a liquid tank.

(Prior Art) Generally, a cooling cycle is incorporated in an air conditioner for a vehicle in order to cool the temperature of air blown into a vehicle cabin. As shown in Japanese Utility Model Laid-Open No. 57-61465, a liquid tank is provided in the cooling cycle, in which a refrigerant is temporarily stored and the like. Since the inside of this liquid tank is always kept at a high pressure, when a refrigerant pipe for guiding the refrigerant into and out of the liquid tank is connected to the lid closing the inside of the liquid tank, it must be connected with high airtightness. Is required. Further, because of the improvement of the airtightness and the improvement of the attachment property, it is required that the refrigerant pipe is locked and fixed to the lid and does not rotate.

FIGS. 6 to 9 show a method of processing a refrigerant pipe in a conventional liquid tank in order to satisfy the above-mentioned requirement, and FIG. 12 is a schematic configuration diagram illustrating a main part of the conventional liquid tank.

As shown in FIG. 12, the liquid tank 1 closes an open end of a cylindrical casing 2 which is open on one side with a lid 3,
An end plate 5 to which a refrigerant pipe is attached is joined to the lid 3. The end plate 5 includes a first inlet opening 6a and a first outlet opening 7a through which an inlet pipe 4a and an outlet pipe 4b for guiding the refrigerant into and out of the liquid tank 1 are inserted. And a first bolt receiving hole 9a through which a bolt 8 to be screwed is inserted. The lid 3 also has a second introduction opening 6b, a second lead-out opening 7b, and a second bolt receiving hole 9b, as described above. In addition, the first introduction opening 6a formed in the end plate 5
As shown in FIG. 11, the inner wall of the first opening 7a and the first outlet opening 7a have a knurled portion (hereinafter referred to as a serration portion 10) for better biting with the refrigerant pipe 4 over the periphery thereof.
Is engraved.

Next, for example, a method of processing the introduction pipe 4a when attaching the introduction pipe 4a to the first introduction opening 6a will be described.

First, as shown in FIG. 6, the introduction pipe 4a is connected to the first introduction opening portion.
Insert 6a (step 1). The first introduction opening 6a
Is the inlet pipe 4a from the diameter dimension including its own minimum intersection.
The diameter of the pipe including the maximum intersection is always small, so that the introduction pipe 4a always has some margin.
Can be inserted through the first introduction opening 6a.

Next, as shown in FIG. 7, the introduction pipe 4a is expanded from the insertion side end 11 thereof to a portion which comes into contact with the upper end 12 of the first introduction opening 6a, and is expanded into a processing target portion. A part of the processed part 13 is pressed against the serration part 10 engraved on the inner wall of the first introduction opening part 6a by this expansion (step 2).
In step 2, the first introduction opening 6a formed in the end plate 5 and the biting between the processing portion 13 in the introduction pipe 4a are improved, thereby preventing rotation of the introduction pipe 4a. ing.

Further, as shown in FIG. 8, the introduction pipe 4a is subjected to a so-called swaging process from the insertion side end 11 to a portion abutting on the lower end 14 of the first introduction opening 6a (step). 3). In step 3, the second
The introduction pipe 4a can be inserted into the introduction opening 7a, and the seal ring 15 having a predetermined diameter and used for ensuring airtightness can be easily mounted.

Next, as shown in FIG. 9, a so-called bead process is performed on the introduction pipe 4a to expand a portion where the introduction pipe 4a comes into contact with the lower end portion 14 of the first introduction opening 6a, thereby forming a bead portion 16 ( Step 4). The lower end portion 14 of the first introduction opening portion 6a is provided with a concentric circular recess 17 around the periphery thereof, and the bead portion 16 formed as described above is accommodated in the recess 17. Is done. Also, the upper end 18 of the second introduction opening 6b.
Is provided with a concentric annular and horn-shaped concave portion 19 around the periphery thereof, and the introduction pipe 4a is provided in the concave portion 19.
Is accommodated.

Then, as shown in FIG. 10, the end plate 5 to which the working pipe 4a formed in this way is attached is screwed to the lid 3 by bolts 8 with the sealing pipe 15 interposed between the working pipe 4a. By doing so, the introduction pipe 4a is joined to the liquid tank 1 with airtightness. The same processing as described above is applied to the outlet pipe 4b.

(Problems to be Solved by the Invention) However, in the above-described conventional method of processing the refrigerant pipe in the liquid tank, the refrigerant pipe rotates due to the processing method, and airtightness cannot be ensured. There is a possibility that a problem may occur such that the refrigerant may leak into the air.

That is, the bead processing performed on the introduction pipe 4a in Step 4 described above will be described in detail. The bead portion 16 is formed by pressing the introduction pipe 4a in the axial direction from the insertion side end 11 using a jig. However, at the time of this processing, the portion near the bead portion 16 in the introduction pipe 4a, which has secured the bite with the serration portion 10 by being expanded in step 2, is reduced by the aforementioned pressing force. By acting on the step generated by the contraction in 3, the above-mentioned part crosses around the part and escapes inward of the shaft, so that a clearance part 20 is generated between the introduction pipe 4 a and the serration part 10 (No. 9). As a result, the serration unit 10
When the contact area between the pipe and the introduction pipe 4a is reduced, the holding force is reduced, and there is a possibility that the introduction pipe 4a will eventually rotate.

Further, as described above, the portion of the introduction pipe 4a near the bead portion 16 escapes inwardly of the shaft over the periphery thereof, so that the seal ring 15 is interposed in the introduction pipe 4a to ensure airtightness. However, there is a risk that the airtightness is deviated from the normal position toward the inside of the shaft by the amount of the escape, resulting in deterioration of the airtightness and leakage of the refrigerant.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and when a refrigerant pipe is connected to a liquid tank in communication with the liquid tank, the rotation of the refrigerant pipe is reliably prevented, and the liquid tank is connected with high airtightness. It is an object of the present invention to provide a method for processing a refrigerant pipe.

[Constitution of the Invention] (Means for Solving the Problems) The present invention for attaining the above object is to close an opening end of a cylindrical casing, which is open on one side, with a lid, and to add a refrigerant to the lid. In a liquid tank formed by joining an end plate having an opening to which a pipe is attached, the refrigerant pipe having a larger diameter than the opening is axially shifted by a predetermined distance from an end on the side of insertion into the opening. The refrigerant pipe after the contraction is inserted into the opening, the refrigerant pipe after the insertion is expanded to a uniform diameter, and the refrigerant pipe is pressed against the opening by the expansion. A plurality of beads are formed in the refrigerant pipe after the pressure contact.

(Operation) By adopting the above-described means, the bead portion is formed in the refrigerant pipe machined to have a uniform diameter, so that a portion near the bead portion extends around the periphery of the bead portion during bead machining. A bead portion is formed at a regular position without escaping in the direction. For this reason, the press-contact state is maintained between the refrigerant pipe and the opening, and there is no gap between the two, so that the opening can securely hold the refrigerant pipe,
As a result, the rotation of the refrigerant pipe can be reliably prevented. Also,
By forming the bead portion at the regular position, the seal ring for ensuring the airtightness is also accommodated at the regular position without being shifted as described above. Thereby, the refrigerant pipe can be always connected to the liquid tank with high airtightness. Further, since a bead portion for locking the seal ring is formed, the seal ring is prevented from dropping and being lost.

(Example) Hereinafter, an example of a method of processing a refrigerant pipe in a liquid tank according to the present invention will be described in detail with reference to the drawings. FIGS. 1 to 4 show a method of processing a refrigerant pipe in a liquid tank according to the present invention, and FIG. 5 shows a state of joining of a refrigerant pipe in a liquid tank according to the present invention. Note that the configuration of the liquid tank is the same as that of the conventional example, and the description thereof is omitted. Further, as in the case of the conventional example, a case will be described in which the embodiment of the present invention is applied when the introduction pipe 4a is attached to the first introduction opening 6a.

First, as shown in FIG. 1, an inlet pipe 4a as a refrigerant pipe is swaged over a portion 21 which is separated from the insertion side end 11 by a predetermined distance in the axial direction, and the processed portion is processed.
After the processing, the portion 21 is connected to the upper end 12 of the first introduction opening 6a in the first introduction opening 6a using the introduction pipe 4a as an opening.
(Step 1). As shown in the figure, the swaging process has a U-shaped cross section, has a cylindrical concave portion 22 inside, and has an inner diameter approximately the same as the inner diameter of the processed portion 13 for which contraction is required. Is the first jig
The tube is compressed by pressing 23 in the axial direction. In addition, the swaging is performed such that the diameter including the maximum intersection in the processing target portion 13 is always smaller than the diameter including the minimum intersection in the first introduction opening 6a.
That is, in Step 1, the introduction pipe 4a is allowed to be inserted into the first introduction opening 6a.

Next, as shown in FIG. 2, the introduction pipe 4a is connected until the processed part 13 contracted in step 1 is pressed against the serration part 10 engraved in the first introduction opening 6a. The tube is expanded so as to have a uniform diameter (step 2). In addition, the pipe expanding process includes a second jig having a columnar rod-shaped portion 24 having a spherical tip formed at the tip end, and having an outer diameter dimension substantially the same as an inner diameter dimension of the workpiece 13 to be expanded. The tube is expanded by pressing 25 in the axial direction.

That is, in Step 2, the rotation of the introduction pipe 4a is prevented by pressing the processed portion 13 against the serration portion 10 to improve the bite between the two, and the processed portion 13 has a uniform diameter. It is made to become.

Then, as shown in FIG. 3, a bead forming process is performed on a portion of the processed portion 13 expanded to have a uniform diameter in step 2 where the lower portion 14 of the first introduction opening 6a comes into contact with this. Is applied to form a large bead portion 26 as a bead portion. On the other hand, a small bead portion 27 is formed as a bead portion at a position separated from the large bead portion 26 by a distance substantially equal to the width of the seal ring 15 toward the insertion side end portion 11 (step 3). In the processing of the large bead portion 26, a cylindrical rod-shaped portion 24 having a spherical tip at the tip is formed.
This is performed by pressing a third jig 29 having a peripheral portion 28 surrounding the periphery of the 24 at a predetermined distance in the axial direction. On the other hand, the processing of the small bead portion 27 is performed using a jig (not shown) in which a small spherical body is fixed to the tip end.

That is, in step 3, the processing portion 13 expanded in step 2 so as to have a uniform diameter is used.
In addition, since the large bead portion 26 is formed, the large bead portion 26 does not escape in the axial inner direction at the time of bead processing, so that the large bead portion 26 can be formed at a regular position. In addition, since the large bead portion 26 does not escape inward of the shaft, there is no gap between the introduction pipe 4a and the serration portion 10. Furthermore, small bead part 27
In this case, the seal ring 15 is locked, so that the seal ring 15 is not dropped and lost.

After step 3, if the end plate 5 is attached to the lid 3 with the bolt 8 with the seal ring 15 interposed (FIGS. 4 and 5).
(See the figure), while preventing the rotation of the introduction pipe 4a while maintaining the press-contact state without generating a clearance between the introduction pipe 4a and the serration part 10, the large bead part 26 is formed at a regular position. As a result, the seal ring 15 is also accommodated in the proper position, so that the introduction pipe 4a can be joined to the liquid tank 1 with high airtightness.

Finally, the present invention is applicable not only to liquid tanks but also to any products that are flange-fitted.

[Effects of the Invention] As described above in detail, according to the present invention, the bead portion is formed in the refrigerant pipe processed to have a uniform diameter. The bead portion is formed at a regular position without the portion of the body crossing the periphery and escaping inward of the shaft. For this reason, the press-contact state is maintained between the refrigerant pipe and the opening, and there is no gap between the two, so that the opening can securely hold the refrigerant pipe, and as a result, the refrigerant Pipe rotation can be reliably prevented. In addition, since the bead portion is formed at the regular position, the seal ring for ensuring airtightness is also accommodated at the regular position without shifting, as described above. Thereby, the refrigerant pipe can be always connected to the liquid tank with high airtightness. Moreover,
Since a bead portion for locking the seal ring is formed, a unique effect is obtained in that the seal ring is not dropped and lost.

[Brief description of the drawings]

FIGS. 1 to 3 are diagrams showing a method of processing a refrigerant pipe in a liquid tank according to the present invention step by step, and FIGS. 4 to 5 are processed by a method of processing a refrigerant pipe in a liquid tank according to the present invention. FIGS. 6 to 9 are views showing the state of attachment of the refrigerant pipes, and FIGS. 6 to 9 are diagrams showing a method of processing the refrigerant pipes in the liquid tank according to the conventional example, step by step.
FIG. 11 is a diagram showing an attached state of a refrigerant pipe processed by a method of processing a refrigerant pipe in a liquid tank according to a conventional example, FIG. 11 is a cross-sectional view taken along line II of FIG. 6, and FIG. It is a figure which shows the attachment state of the refrigerant pipe processed by the processing method of the refrigerant pipe in such a liquid tank. 2 ... cylindrical casing, 3 ... lid, 4a ... introduction pipe (refrigerant pipe), 4b ... outlet pipe (refrigerant pipe), 5 ... end plate, 6a ... first introduction opening (open) Holes), 7a: first lead-out opening (opening), 26: large bead (bead), 27: small bead (bead).

Claims (1)

(57) [Claims] An open end in which an open end of a cylindrical casing (2) which is open on one side is closed by a lid (3), and refrigerant pipes (4a, 4b) are attached to the lid (3). In the liquid tank formed by joining the end plates (5) provided with the openings (6a, 7a), the refrigerant pipes (4a, 4) having a diameter larger than that of the openings (6a, 7a) are provided.
b) is axially contracted by a predetermined distance from the end on the insertion side into the opening (6a, 7a), and the refrigerant pipe (4a, 4b) after the contraction
Through the openings (6a, 7a), expand the refrigerant pipes (4a, 4b) after insertion into a uniform diameter, and open the refrigerant pipes (4a, 4b) by the expansion. A method for processing a refrigerant pipe in a liquid tank, characterized in that a plurality of beads (26, 27) are formed in the refrigerant pipes (4a, 4b) after being pressed against the parts (6a, 7a).